Trac #16722: OA(17,560)

A new OA(17,560) from the same paper as #16662. It is the last one.

URL: http://trac.sagemath.org/16722
Reported by: ncohen
Ticket author(s): Nathann Cohen
Reviewer(s): Vincent Delecroix
Trac #16757: Organize the V(m,t) vectors into a dictionary

There are many Vmt vectors coming, and while the data of a Vmt is only
<20 integers, adding one in Sage takes a total of 40 lines of code,
because of the doc and everything (aways copy/pasted).

With this patch, all the V(m,t) vectors are now contained in a
dictionary, and adding one takes 3 lines (one for the integers, one for
the bibliographical reference, and one for the index at the top of the
file).

Nathann

URL: http://trac.sagemath.org/16757
Reported by: ncohen
Ticket author(s): Nathann Cohen
Reviewer(s): Vincent Delecroix
Trac #16834: Change ring fails for affine morphisms.

When calling the change ring function on affine morphisms an index out
of bounds error occurs:

{{{

 sage: A.<x,y,z> = AffineSpace(RR,3)
 sage: h = Hom(A,A)
 sage: f = h([x^2+1.5,y^3,z^5-2.0])
 sage: f.change_ring(CC)

}}}

URL: http://trac.sagemath.org/16834
Reported by: gjorgenson
Ticket author(s): Grayson Jorgenson
Reviewer(s): Ben Hutz
Trac #16763: New OA for n=189, plus some others through Vmt vectors

A new OA for n=189 is implemented from its construction.

With a collection of Vmt vectors we also get new OA for n=1080, 1158,
1314, 1340, 1574, 2198, 2484, 2588, 2978, 892, 1068, 1134, 1992, 2058,
2850, 3004, 3510, 4302, 4500.

Nathann

URL: http://trac.sagemath.org/16763
Reported by: ncohen
Ticket author(s): Nathann Cohen
Reviewer(s): Vincent Delecroix
Trac #16859: Resolvable incomplete orthogonal arrays

I forgot that in #16655 and I need it in #16780. Incomplete Resolvable
Orthogonal Arrays !

Nathann

URL: http://trac.sagemath.org/16859
Reported by: ncohen
Ticket author(s): Nathann Cohen
Reviewer(s): Vincent Delecroix
Trac #16802: difference family database

Import the database from the Handbook of combinatorial design inside
Sage.

URL: http://trac.sagemath.org/16802
Reported by: vdelecroix
Ticket author(s): Vincent Delecroix
Reviewer(s): Nathann Cohen
Trac #16863: twin prime difference sets

Some new difference set (not very visible... but still new BIBD in
perspective).

URL: http://trac.sagemath.org/16863
Reported by: vdelecroix
Ticket author(s): Vincent Delecroix
Reviewer(s): Nathann Cohen
Trac #16869: faster prime_powers

The function `prime_powers` in `sage.rings.arith` was using the symbolic
ring... it would be faster to use a `sleep(10)` and avoid it.

URL: http://trac.sagemath.org/16869
Reported by: vdelecroix
Ticket author(s): Vincent Delecroix
Reviewer(s): Nathann Cohen
Trac #16833: Use MacCauley Resultant to compute resultant of projective morphisms for dim >1

Currently resultants for dim greater than one not implemented, changing
to call MacCauley resultants for higher dimensions.

URL: http://trac.sagemath.org/16833
Reported by: jdefaria
Ticket author(s): Joao de Faria
Reviewer(s): Ben Hutz